Some websites are saying thriller is free on XBLA but I can't find any free copy....is this just a rumor or am i crazy..

It's not free any more, offer ended.

how did that happen??? i just got the tweet like 3 hours ago

According to Destructoid, it's a U.S.-only deal (http://www.destructoid.com/get-michael-jackson-s-thriller-for-free-on-xbox-live-137807.phtml). Story doesn't mention if it is a limited-time download.